Squeegee device for applying liquid or viscous material to a web

ABSTRACT

An apparatus for applying a liquid or viscous material to a traveling web by means of a roller squeegee includes a blade squeegee positioned upstream of said roller squeegee, as viewed in the direction of movement of the web.

United States Patent 1191 1111 3,919,973

Zimmer 5] Nov. 18, 1975 1 1 SQUEEGEE DEVICE FOR APPLYING 3.592.132 7/1971 Weber 101/119 LIQUID OR VISCOUS MATERIAL o A 3.596.595 8/1971 Zimmer et a1, H 101/120 WEB 3.774.533 11/1973 lchinose 101/119 3807302 4/1974 Kudlich 101/119 [76] n entor: Johannes Zimmer, Ebentaler Strabe 3.811.378 5/1974 Bohm 101/119 133, A-9020 Klagenfurt, Austria 22 F1 d A l 1974 FOREIGN PATENTS OR APPLICATIONS I 1 513,905 10/1939 United Kingdom 101/120 [21] Appl. No.: 456,767

Primary E.ranziner--Mervin Stein [30] Foreign Application Priority Data Assistant Erumz'ner-Douglas Salser Mar. 30, 1973 Austria 2842/73 Fimkwenderoth Lind Ponack [52] US. Cl. 118/406; 101/120; 101/122;

118/213; 118/301 [57] ABSTRACT [51] Int. Cl. BOSC 3/00; 8411- 15/08 A aratus for applying a liquid or viscous material Fleld of Search to a traveling eb means of a roller squeegee in 118/ 5 /1 122, 129 cludes a blade squeegee positioned upstream of said r011er squeegee, as viewed in the direction of move- [56] References Cited ment of the web.

UNITED STATES PATENTS 1,945,065 1/1934 Miisslang et a1, 118/110 5 3 Drawmg F'gures US. Patent Nov. 18,1975 S heet10f3 3,919,973

U.S. Patent Nov. 18, 1975 Sheet 2 of3 3,919,973

Fig.2

US. Patent Nov. 18, 1975 Sheet30f3 3,919,973

SQUEEGEE DEVICE FOR APPLYING LIQUID OR VISCOUS MATERIAL TO A WEB BACKGROUND OF THE INVENTION The invention relates to an apparatus for applying liquid or viscous materials to a web in connection with the employment of a roller squeegee.

In experiments involving a cylindrical stencil screenprinting machine, which was equipped with a roller squeegee applied thereagainst by magnetic pressure, it was determined that the roller squeegee was shifted through the resistance of the printing ink in the direction of movement of the stencil wall, at high speeds of printing and during the employment of a highly-viscous printing ink. In order to avoid this effect, which exerts a decisive detrimental action on the quality of printing, for example, the Austrian Pat. No. 266,024 proposed a support element, which was arranged downstream of the roller squeegee, in the direction of rotation of the cylindrical stencil.

With this device it was indeed possible to control a higher speed of printing, but during a further increase in the printing speed the roller squeegee was pressed stronger and stronger against the support element, owing to the increasing pressure of the ink sump. This increases the friction between the roller squeegee and the support element, the value of friction possibly exceeding in extreme cases the value of friction between the stencil and the roller squeegee, so that rotation of the squeegee is stopped and the quality of printing is lowered to a considerable extent.

The same problem occurs also in the case where a web is coated without the use ofa stencil, such as in the application of an adhesive or the like over the entire surface. Indeed, also here large masses of compound to be applied are gathered occasionally upstream of the roller squeegee and a rotating compound sump is formed.

SUMMARY OF THE INVENTION The object of the invention is to eliminate the disadvantage mentioned above. This is attained through the arrangement of a blade squeegee upstream of the roller squeegee and by feeding the ink upstream of the blade squeegee.

The formation of an ink sump upstream of the roller squeegee is prevented in this manner. Hence, a strong force pushing away the roller squeegee likewise no longer occurs.

A further advantage of the invention is manifested in its application to a cylindrical stencil screen-printing machine. Only a definite amount of ink still reaches the roller squeegee in this case specifically the amount which was pressed by the preceding blade squeegee into the openings of the stencil. The roller squeegee then presses the ink into such amount of material.

On the other hand, with the devices customarily employed until the present time in rotary screen printing it was readily possible that an excess of ink reached the web, of material especially in printing materials pos' sessing a low capacity of absorption, e.g., paper, so that relatively long drying intervals had to be maintained between the separate printing stations. Such drying periods can now be shortened substantially by use of the present invention and the printing speed can thus be increased.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be explained in more detail with reference to the attached drawings.

FIG. I is a cross-section illustrating the application of the invention to a cylindrical stencil screen-printing machine.

FIG. 2 is a cross-section illustrating the application of the invention in a non-stencil machine; and

FIG. 3 is a cross'section illustrating a modification of the device of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. I, printing ink is supplied through an ink tube 5, passes out through openings 9 and forms an ink sump 4 upstram of a blade squeegee 3, as seen in the direction of rotation of a cylindrical stencil 1, which blade squeegee is attached to ink tube 5. Blade squeegee 3, which advantageously contacts the stencil outside the area of contact of stencil l and a web of materials 6, wipes clean the inner side of stencil 1 and, at the same time, presses ink 4 into the openings of stencil 1. Web 6 contacts a printing support 7 running over drivable rollers. The web takes along stencil 1 owing to the pressure exerted thereon by roller squeegee 2. Roller squeegee 2 is forced against the inner surface of stencil l by pressure, in this case by means of a magnet bar 8 arranged under printing base 7, but the application of pressure could also be effected mechanically. Stencil I, thus set in rotation, conveys ink 4 situated in its openings to roller squeegee 2, which presses it into web 6.

In contrast with the embodiment of FIG. I, wherein blade squeegee 3 contacts stencil 1 outside the area of contact B of stencil l and web 6, the embodiment of FIG. 3 shows the contact of blade squeegee 3 with stencil 1 within the contact zone B. The arrangement of FIG. 3 makes it possible to obtain certain printing effects, e.g., softer outlines of the pattern, while rather sharper outlines are obtained with the arrangement of FIG. 1. Besides, squeegee 3 in the embodiment of FIG. 3 is held in a guide 13, which is attached to ink tube 5, and consists of magnetizable material. The pressureapplication of blade-squeegee 3 and roller squeegee 2 is effected by means of a magnet system 12 arranged below printing base 7 and consisting of a magnet bar or a magnet roller.

However, the invention is not restricted to the employment in connection with screen-printing stencils, such as round, band and flat stencils. For example, the invention can also be employed with success in area 1 application of viscous materials to a web, as illustrated, for example, in FIG. 2.

The coating material, e.g., an adhesive, is fed upstream of the blade squeegee and forms a sump 4 in front of such squeegee. The blade squeegee consists of a loop 3' of thin elastic material, e.g., nickel, and a magnetizable rod 10 inserted into loop 3'. Rod 10 is pressed against web 6 by means of a magnet bar 8 arranged below printing base 7, so that the coating material is wiped off in a thin film onto the web. The coating material, which now adheres to the surface of.web 6 is then pressed deeper into the web by roller squeegee 2 that is pressed by magnet bar 8 against the web. Loop 3' is attached with its upper end to a beam 11 that is held in a vertically adjustable position in a machine frame that is not illustrated in the drawings. Accordingly, by varying the distance between beam 11 and web 6, the coating material can be wiped to a greater or smaller extent by the blade squeegee and the thickness of the coating varied, or it is possible to obtain a coating of the desired thickness. In the illustrated exemplified embodiment, separate magnet bars 8 and 8' are provided for each of the blade squeegee and also for roller squeegee 2. However, it is also possible to provide only a short distance between the two squeegees and to apply pressure to the two squeegees by means of a single magnet bar. The ratio of pressure of the blade squeegee and the roller squeegee depends in this case largely on the magnetic properties of the materials that are employed in roller squeegee 2 and rod 10 of the blade squeegee and on the cross sections selected.

I claim: 1. A printing apparatus for applying a liquid or viscous printing material to a traveling web, said apparatus comprising:

a moving printing base supporting and transporting a web; a stencil screen mounted in contact with said web,

said screen having therein perforations; means for supplying said liquid or viscous printing material to a position on said stencil screen; blade squeegee means mounted to permanently contact said stencil screen for pressing said liquid or viscous printing material into but not through said perforations in said stencil screen; and

4 roller squeegee means permanently contacting said stencil screen at a position downstream of said blade squeegee means, as viewed in the direction of travel of said web, for pressing said liquid or viscous printing material positioned in said perforations through said perforations onto said web.

2. An apparatus as claimed in claim 1, wherein said stencil screen comprises a cylindrical stencil screen mounted for rotation in contact with said web, said blade squeegee means and said roller squeegee means being positioned to contact the interior of said screen.

3. An apparatus as claimed in claim 2, wherein both said roller squeegee means'and said blade squeegee means contact said screen in the area of contact between said screen and said web.

4. An apparatus as claimed in claim 1, wherein said blade squeegee means is positioned closely adjacent said roller squeegee means.

5. An apparatus as claimed in claim 1, wherein said blade squeegee means and said roller squeegee means are formed of magnetizable material, and further comprising magnet means positioned on the side of said web opposite said blade squeegee means and said roller squeegee means'for causing said blade squeegee means and said roller squeegee means to be pressed toward said web. 

1. A printing apparatus for applying a liquid or viscous printing material to a traveling web, said apparatus comprising: a moving printing base supporting and transporting a web; a stencil screen mounted in contact with said web, said screen having therein perforations; means for supplying said liquid or viscous printing material to a position on said stencil screen; blade squeegee means mounted to permanently contact said stencil screen for pressing said liquid or viscous printing material into but not through said perforations in said stencil screen; and roller squeegee means permanently contacting said stencil screen at a position downstream of said blade squeegee means, as viewed in the direction of travel of said web, for pressing said liquid or viscous printing material positioned in said perforations through said perforations onto said web.
 2. An apparatus as claimed in claim 1, wherein said stencil screen comprises a cylindrical stencil screen mounted for rotation in contact with said web, said blade squeegee means and said roller squeegee means being positioned to contact the interior of said screen.
 3. An apparatus as claimed in claim 2, wherein both said roller squeegee means and said blade squeegee means contact said screen in the area of contact between said screen and said web.
 4. An apparatus as claimed in claim 1, wherein said blade squeegee means is positioned closely adjacent said roller squeegee means.
 5. An apparatus as claimed in claim 1, wherein said blade squeegee means and said roller squeegee means are formed of magnetizable material, and further comprising magnet means positioned on the side of said web opposite said blade squeegee means and said roller squeegee means for causing said blade squeegee means and said roller squeegee means to be pressed toward said web. 